package demo2;

public class Computer {
    public void powerOn() {
        System.out.println("开机");
    }
    public void powerOff() {
        System.out.println("关机");
    }
    public void useDevice(IUSB usb) {
        usb.openDevice();
        if(usb instanceof Mouse) {
            ((Mouse)usb).click();
        } else {
            ((KeyBoard)usb).type();
        }
        usb.closeDevice();
    }

    public static void main(String[] args) {
        Computer computer = new Computer();
        computer.powerOn();
        computer.useDevice(new Mouse());
        computer.useDevice(new KeyBoard());
        computer.powerOff();
    }
}
